Although old-school machinists sometimes want the mechanical vernier scale on their trusty calipers, many customers these days purchase calipers with a digital readout. These fashions usually include extra options like differential measurements, or a “hold” operate for these conditions the place it’s important to maneuver the instrument someplace deep inside a machine. Another helpful function is an information hyperlink that permits you to log your measurements on a pc immediately as an alternative of manually getting into all of the values.
The VINCA-branded caliper that [Liba2k] purchased has such an information hyperlink function, which requires a USB adapter that’s bought individually. There is a micro-USB connector on the software itself, however as an alternative of implementing a USB interface, that is used to hold a proprietary serial protocol — a design choice that should be categorised as a felony for those who ask us. Rather than shopping for the official USB adapter, [Liba2k] decoded the protocol and constructed his own interface called VINCA Reader that can connect through either USB or Wi-Fi.
The serial format turned out to be a easy serial bus that clocks out 24 bits at a time. In order to adapt its 1.2 V sign stage to the three.3 V utilized by an ESP32, [Liba2k] designed a easy stage shifter circuit utilizing a handful of discrete elements. The ESP can talk with the pc via its Wi-Fi interface, for which [Liba2k] wrote a spreadsheet-like utility; alternatively, an strange USB cable could be related to emulate a keyboard to be used with every other software program.
With its added Wi-Fi function, the VINCA Reader is definitely extra full than the official USB adapter, and can in all probability be cheaper as nicely. The serial interface seems to be frequent to all caliper producers, though many went for a more sensible connector than micro-USB. An automated readout system is especially helpful if it’s important to make thousands of similar measurements.